az-eq5gt AZ-EQ5GT Encoders.

[Coastliner]

Hello all,

I have just discovered the  benefit of turning off the auxiliary encoders on my AZ-EQ5GT.  Goto after a PA puts the target in the fov first time with no star align or platesolving. My question is does the mount also have primary or main encoders? or does it rely on accurate home positioning and accurate stepper motors for goto? 

[Dr_Ju_ju]

From what I can see on the Spec's, it's just got the one set of encoders.

If the mount is stationary ? you're driving it using the handset, then as long as you have a good PA, and have at least done one iteration of the alignment routine, then it should be pretty good at getting on target.

FYI, on my AZEQ6 I've always had the encoder disabled, but then I also use Plate solving to ensure target accuracy 

 

[Coastliner]

Thanks. I use Eqmod and have only just disabled the encoders after a few years of owning the mount. The difference makes me think that the encoders are a liability!

[SamAndrew]

I think the encoder is only for PPEC, however I never found it worked very well and ultimately continued to use it without the encoder.

[jambouk]

If this mount has “freedom find” then there are two sets of encoders. It is known with the AZEQ6 that if you turn the freedom find encoders off, the GOTO accuracy improves.

[Coastliner]

1 hour ago, jambouk said:

If this mount has “freedom find” then there are two sets of encoders. It is known with the AZEQ6 that if you turn the freedom find encoders off, the GOTO accuracy improves.

Ok, my mount has Freedom Find. Do you know of any documentation that states that there are two sets of encoders? Is one set integral to the motors and the other set external?  

[jambouk]

The manual calls the freedom find encoders “Auxiliary Encoders” which suggests they are not the primary ones. If these can be turned off, yet the GOTO still works, there must be another set of encoders [or the like] on both the RA and Dec.

[jambouk]

The synscan manual also says:

”6.4 Enable/Disable Auxiliary Encoder
Some Sky-Watcher’s mounts are equipped with auxiliary encoders on their primary axes to support manually rotating the axes without worrying about losing the mount’s alignment sta- tus. Users may turn off the auxiliary encoder to obtain the best pointing accuracy. The auxiliary encoder can be turned on again at any time for manually moving the mount.
1. Access the menu “SETUP\Aux. Encoder” and press the ENTER key.
2. Use the scroll keys to select between “Enable” or “Disable” and press the ENTER key.
Note:
• After re-enabling the auxiliary encoders, it is recommended to use the direction keys to move both axes for a little bit before asking the hand control to locate an object.
• For mounts which do not have auxiliary encoders, the hand control will display “Not availi- able !”

[Coastliner]

jambouk, this is exactly my reasoning, I'm pleased that you have come up with the same.  I have been discussing this with someone else who insists  that the aux encoders are the only ones, and if they are disabled the mount counts the stepper motor steps from the home postions to  set its position in the heavens. It would be good to find evidence of two encoder sets.

[Coastliner]

Found this: https://themcdonalds.net/richard/wp/basics-of-go-to-mounts/

My conclusion is that all gt mounts have encoders.  The AZ-EQ5GT has aux encoders that support freedom find.

[jambouk]

This section of the synscan manual suggests there are two sets of encoders; all synscan GOTO mounts have a set of GOTO encoders.

“8.11 Synchronizing Encoders
If the mount loses the correct position of any of its two axes (for example, the axis is manually moved), the pointing accuracy will be poor when the SynScan hand control tries to locate an object.
Providing the base of the mount is not moved, users can recover the pointing accuracy with the “Synchronize Encoder” operation:
1. Access the menu “Setup \ Sync. Encoder” and press the ENTER key.
2. Use the scroll keys to select an alignment star and press the ENTER key. The mount will
point the telescope towards the alignment star.
3. After the mount has stopped, use the direction keys to center the alignment star in the
eyepiece, then press the ENTER key to confirm.
4. The SynScan hand control will display “Sync Encoder Completed”. Press any key to exit.”